* solenc/inc/settings.mk: Drop MSVC 2003 section.

* solenc/inc/tg_compv.mk: Set COMNAME appropriately for 64-bit build.

* solenc/inc/wnt.mk: Drop unsupported compiler version sections.

* solenc/inc/wntmsci11.mk: Look for the CL_X64 make variable, not
  cl_x64. Drop duplicate definitions already put in the environment by
  set_soenv.in.